Optimization of Forward and Reverse Electrical Characteristics of GaN-on-Si Schottky Barrier Diode Through Ladder-Shaped Hybrid Anode Engineering

In this work, a Schottky Barrier Diode (SBD) with an optimized ladder-shaped hybrid anode (LSHA) is demonstrated. The SBD devices in this work were fabricated on a GaN-on-Si wafer with in situ Si3N4 cap layer. To form the LSHA, a two-step recessed process was implemented. For device optimization, the recess depths of the two recess steps were carefully optimized. Devices with different LSHA recess profiles were fabricated, and their electrical characteristics were evaluated by measuring the forward current, reverse current and breakdown voltage (BV). Optimized device exhibited a low reverse leakage current ( ${I}_{R}$ ) of ${5.66} \times {10} ^{-{8}}$ (A/mm), a low turn-on voltage ( ${V}_{T}$ ) of 0.315 V, and a BV over 1000 V. In addition, ${I}_{R}$ (A/mm) versus ${V}_{T}$ ( ${V}$ ) of this work and ${R}_{{\text {on}, \text {SP}}}$ ( $\text{m}\Omega \cdot $ cm2) versus BV ( ${V}$ ) of this work are benchmarked. We demonstrated the lowest ${I}_{R}$ among the GaN SBDs with ${V}_{T} < 0.4$ V and the outstanding performance of ${R}_{{\text {on}, \text {SP}}}$ (0.88 $\text{m}\Omega \cdot $ cm2) with a hard BV of over 1000 V (1020 V) using the LSHA-SBD.